Re: Inservice Inspection

[magnum8@banet.net]

Good points, Eric. In fact, I've seen a real effort in recent years to
accomplish ISI on auxiliary (perhaps I should say ex-drywell or
ex-containment) systems during operations to reduce the work load on the
outage schedule. I have to watch those blanket statements...However, as you
also noted, it can be a difficult proposition and frequently impossible.
Definitely leads to some interesting cost benefit evaluations.

Another point that you alluded to may not be fully understood or appreciated
by non-power reactor health physics professionals. The regulatory and
political pressure to reduce both individual and collective doses at the
reactors became increasing intense during the '90s. Many factors contributed
to this. Genuine concern over radiological risk (let's face it, the 1,000+
person-rem outages weren't pretty), embarrassment over our (U.S.) dose
performance compared to other countries, the "ALARA rule" becoming a
"shall", etc. With power reactor HP professionals being judged by the bottom
line (collective dose and number of citations) by the regulator, auditors
(INPO, etc.), and non-HP licensee management, the temptation to push for "as
low as possible" (remember ALAP?) as opposed to ALARA doses has been very
real for many of us. And those of us that have been there know that what is
"ALARA" can frequently depend on what hat you are wearing at the time of
decision. I've mentioned this to emphasize that now we frequently are well
beyond the realization of a true risk benefit - at least in my opinion.

Chris Wend
christopher_wend@bedison.com
magnum8@banet.net

ERIC GOLDIN wrote:

>      One last point about reactor inservice inspections.  Quoting from
>      the press release:
>
>      "the RI-ISI methodology is so focused, workers can reduce by up
>      to 75 percent the number of inspections they must perform in
>      radiological areas when compared to traditional inspection
>      methodology,'' he said.  Therefore, RI-ISI can easily reduce
>      cumulative dose rates by 60 REM or more over a 10-year period..."
>
>      Remember that any technology that can reduce the number of
>      inspections is also going to cost a whole lot less ($ in addition
>      to dose).  Therefore, in this day of cost competitive electricity
>      generation, risk-informed ISI has a significant $-savings.  As
>      far as the dose savings, 60 person-rem over 10 years may not
>      sound like much, but when plants are scrambling to reduce
>      personnel exposure wherever possible and totals for a refueling
>      outage hover around 100 person-rem, 10 or so avoided is a pretty
>      big number (assuming a refueling every 20-odd months, yada
>      yada...)
>
>      And by the way, some ISI can be conducted when the plant is
>      running, such as inspections of safety injection piping, shutdown
>      cooling (RHR to you Westinghouse folks), as long as it's outside
>      containment.  May not get done often due to schedules, personnel
>      availability, system operability requirements, etc.
>
>      Eric Goldin,  not my employer's opinion, only mine
>      <goldinem@songs.sce.com>
>
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